The present invention relates to methods of bonding strain gages to members to be strained; and, in particular relates to adhesive bonding of foil-type electrical resistant strain gages to the strained structural member.
Heretofore, it has been common practice to bond the aforesaid foil-type strain gages to the member to be strained by placing a suitable bonding material such as an air curing adhesive on the reverse side of the foil strain gage, positioning the gage onto the structure to be strained and applying mechanical pressure to hold the gage in place while the adhesive is permitted to cure. Typically, padded mechanical clamps have been used to hold the gages in place and to apply the pressure thereon. However, it has been found difficult where mechanical clamping is used to obtain uniform pressure over the surface of the strain gage. Furthermore, the use of mechanical clamps has made it extremely difficult to maintain application of the same pressure from gage to gage. The result has been poor uniformity in electrical performance of the gages and in some cases has resulted in nonrepeatability of the gage readings due to imperfect bonding of the gage to the structure to be strained.